Shooting multiple images for HDR: i understand that you can take a series of photos say 3 or 5 photos) at different exposures (like -1 0 +1), then combine them is a photo processing...

leftyD500 Loc: Ocala, Florida

i understand that you can take a series of photos say 3 or 5 photos) at different exposures (like -1 0 +1), then combine them is a photo processing program, like photomatix, to bring out the best highlights, midtones, and shadows in one photo. My question is, if you shoot in raw, you have captured the entire range (or most of it anyway) of highlights, and shadows. Why could you not save the raw photo that (supposedly) properly exposed, then in ACR, overexpose a copy of the original by +1 and underexpose a copy of the original by -1, then combine those three photos either in photoshop, or in photmatix?

rmalarz Loc: Tempe, Arizona

Depending on how you meter the scene, you may not have captured the entire range. If one spot meters the brightest part of the scene and places that in Zone VIII or IX, then one would capture the maximum range the scene has to offer. This, of course, is dependent on the capabilities of the camera's sensor. With a capable sensor, and proper exposure, one rarely needs to resort to HDR techniques.
--Bob

jradose wrote:

i understand that you can take a series of photos ... (show quote)

via the lens Loc: Northern California, near Yosemite NP

I understand that some people do what you describe. However, doing that does not give you the same dynamic range that putting two or three photos together does, generally about 10 stops. Do you need that wider dynamic range? Sometimes yes and sometimes no. It's generally good to start out with the most file information possible, but if you are happy with your results and what you do works well for you then that is good enough. Try out both ways and see what works for you.

CaltechNerd Loc: Whittier, CA, USA

I happen to always shoot raw (not the right way, just what works for me). There are night scenes with bright lights that my camera, and probably no camera, is going to completely capture. HDR and other techniques applied to widely bracketed shots can capture this. Is this a common need, absolutely not. Is it nice to have a solution when it is a need, absolutely :-)

TriX Loc: Raleigh, NC

My thought is that you can expand the dynamic range of a digitized (or analog) signal by multiplying the values by a constant. That can be either linear in each direction around a mid value or above (or below) a given value/threshold. But if you have "blown the highlights" by overexposing, you cannot expand/recreate information that does not exist. My guess is that just as in the audio world, there are "penalties" (potential distortion) to this process, but I would be interested to hear the thoughts on this from those that are more knowledgeable than myself.

bsprague Loc: Lacey, WA, USA

jradose wrote:

i understand that you can take a series of photos ... (show quote)

"My question is, if you shoot in raw, you have captured the entire range (or most of it anyway)....."

The dynamic range of most current sensors now is about a dozen f-stops. That is enough for a lot of "normal" scenes. But, if the range of light is greater than a dozen f-stops your camera will have blocked shadows and burned highlights where no detail can be seen. You will only see blackness and whiteness.

Some scenes will have a range of 20, or more. Think of a dimly lit room with view windows where you want to see detail in the furniture and the view outside. Or a sunset at the beach behind a driftwood log in deep shadow. Some photographers with shoot the bracketed images and combine them automatically in HDR software. Others will shoot separate and carefully exposed shots and use Photoshop to combine selected portions of the exposures.

Bracketing for HDR processing can be a waste of effort if the scene has only a moderate range of "brightness". In that case a RAW capture will get the entire range, or at least most of it.

CO

Photomatix can do what you were describing about taking a single image and creating two exposures from it. It has the option of loading a single image. It splits the single image into two exposures and then does tone mapping on those. I've done it. It's amazing what it can do with a single image.

rmalarz Loc: Tempe, Arizona

If one knows their camera's capabilities and measures exposure correctly, one can attain the complete range with one exposure even if bright light is present.

http://www.uglyhedgehog.com/t-438348-1.html

--Bob

CaltechNerd wrote:

I happen to always shoot raw (not the right way, just what works for me). There are night scenes with bright lights that my camera, and probably no camera, is going to completely capture. HDR and other techniques applied to widely bracketed shots can capture this. Is this a common need, absolutely not. Is it nice to have a solution when it is a need, absolutely :-)

rjaywallace Loc: Wisconsin

CO wrote:

Photomatix can do what you were describing about taking a single image and creating two exposures from it. It has the option of loading a single image. It splits the single image into two exposures and then does tone mapping on those. I've done it. It's amazing what it can do with a single image.

You are quite right, CO!

For the OP (person who posed the original question) - be aware that UHH has an entire section concerning "HDR Photography - Before and After". You might go there for more details on the capability of Photomatix and other HDR applications. /Ralph

TheDman Loc: USA

bsprague wrote:

"My question is, if you shoot in raw, you hav... (show quote)

TheDman Loc: USA

rmalarz wrote:

If one knows their camera's capabilities and measures exposure correctly, one can attain the complete range with one exposure even if bright light is present.

http://www.uglyhedgehog.com/t-438348-1.html

--Bob

Now imagine if you wanted to properly expose what was behind that vent.

rmalarz Loc: Tempe, Arizona

I did properly expose what was behind the vent.
--Bob

TheDman wrote:

Now imagine if you wanted to properly expose what was behind that vent.

TheDman Loc: USA

rmalarz wrote:

I did properly expose what was behind the vent.
--Bob

It has zero detail. Imagine if you wanted to capture the detail of what was behind it.

rmalarz Loc: Tempe, Arizona

There's a good reason for that, which seems to have escaped you. There is no detail behind the vent, just a light.

Similarly, I wanted to capture the details of this set of lights, as the texture of the light itself was quite interesting.

http://www.uglyhedgehog.com/t-462142-1.html

--Bob

TheDman wrote:

It has zero detail. Imagine if you wanted to capture the detail of what was behind it.

TheDman Loc: USA

rmalarz wrote:

There's a good reason for that, which seems to have escaped you. There is no detail behind the vent, just a light.

Similarly, I wanted to capture the details of this set of lights, as the texture of the light itself was quite interesting.

http://www.uglyhedgehog.com/t-462142-1.html

--Bob

Then why are you using it as some sort of example of capturing the entire tonal range of a scene? Blowing out the highlights is not capturing a wide tonal range.